Monomers and polymers for optical elements

ABSTRACT

An optical element includes a first lens; a cover; and a cured matrix polymer sandwiched between the first lens and the cover; the matrix polymer, prior to curing, having a monomer mixture dispersed therein; the matrix polymer being selected from the group consisting of polyester, polystyrene, polyacrylate, thiol-cured epoxy polymer, thiol-cured isocyanate polymer, and mixtures thereof; and the monomer mixture comprising a thiol monomer and at least one second monomer selected from the group consisting of ene monomer and yne monomer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is continuation of U.S. application Ser. No.10/936,030, filed Sep. 7, 2004, and entitled Monomers and Polymers forOptical Elements, the entirety of which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to monomeric and polymeric materials, and tostabilized mixtures of monomeric and polymeric materials useful formaking optical elements such as lenses.

2. Description of the Related Art

Optical elements such as eyeglass lenses are typically made by casting,grinding and/or polishing lens blanks made from glass or plastics suchas polycarbonate, Finalite™ (Sola), MR-8 polymer (Mitsui), anddiethylene glycol bis(allylcarbonate)polymer (CR-39) (PPG Industries).However, lenses made using these materials and fabrication techniquesare only capable of correcting relatively simple optical distortions.Other fabrication techniques and polymer compositions have beendeveloped to produce lenses that correct more complicated opticaldistortions. However, the commercialization of such lenses has beencomplicated by the relatively small number of suitable polymercompositions currently available. Polymer compositions such as thosedescribed in U.S. Pat. Nos. 5,236,970; 5,807,906; 6,391,983; and6,450,642 are not entirely satisfactory. Hence, there is a need forpolymer compositions suitable for the fabrication of optical elements,and particularly for optical elements capable of correcting complicatedoptical distortions.

SUMMARY OF THE INVENTION

A preferred embodiment provides a composition comprising: a matrixpolymer having a monomer mixture dispersed therein, the matrix polymerbeing selected from the group consisting of polyester, polystyrene,polyacrylate, thiol-cured epoxy polymer, thiol-cured isocyanate polymer,and mixtures thereof; the monomer mixture comprising a thiol monomer andat least one second monomer selected from the group consisting of enemonomer and yne monomer. Another preferred embodiment provides a methodfor making such a composition comprising intermixing, in any order, thematrix polymer, the thiol monomer and the second monomer.

Another preferred embodiment provides a composition comprising a mixturethat comprises a first polymer and a second polymer, the first polymerbeing selected from the group consisting of polyester, polystyrene,polyacrylate, thiol-cured epoxy polymer, thiol-cured isocyanate polymer,and mixtures thereof; the second polymer being selected from the groupconsisting of thiol-ene polymer and thiol-yne polymer; the mixturecomprising at least one region in which the first polymer has a firstdegree of cure and the second polymer has a second degree of cure thatmay be different from the first degree of cure. Another preferredembodiment provides a method for making such a composition, comprising:providing a composition, the composition comprising a matrix polymerhaving a monomer mixture dispersed therein; the matrix polymer beingselected from the group consisting of polyester, polystyrene,polyacrylate, thiol-cured epoxy polymer, thiol-cured isocyanate polymer,and mixtures thereof; the monomer mixture comprising a thiol monomer anda second monomer selected from the group consisting of ene monomer, ynemonomer, and mixtures thereof; and polymerizing at least a portion ofthe monomer mixture to form the second polymer. Preferably, thepolymerizing of the monomer mixture comprises irradiating thecomposition at ambient or elevated temperature.

Another preferred embodiment provides a compound of the formula

in which n is an integer in the range of about 1 to about 6.

Another preferred embodiment provides a kit comprising: a firstcontainer comprising a thiol monomer; and a second container comprisinga matrix polymer selected from the group consisting of polyester,polystyrene, polyacrylate, epoxy polymer, isocyanate polymer, andmixtures thereof; and a second monomer selected from the groupconsisting of ene monomer and yne monomer.

Another preferred embodiment provides an optical element, comprising: afirst lens; a cover; and a matrix polymer sandwiched between the firstlens and the cover; the matrix polymer having a monomer mixturedispersed therein; the matrix polymer being selected from the groupconsisting of polyester, polystyrene, polyacrylate, thiol-cured epoxypolymer, thiol-cured isocyanate polymer, and mixtures thereof; and themonomer mixture comprising a thiol monomer and at least one secondmonomer selected from the group consisting of ene monomer and ynemonomer. Preferably, the cover is a lens, plano or coating. Morepreferably, the first lens is a lens blank.

Another embodiment provides an optical element, comprising: a firstlens; a cover; and a polymer mixture sandwiched between the first lensand the cover, the polymer mixture comprising a first polymer and asecond polymer; the first polymer being selected from the groupconsisting of polyester, polystyrene, polyacrylate, thiol-cured epoxypolymer, thiol-cured isocyanate polymer, and mixtures thereof; thesecond polymer being selected from the group consisting of thiol-enepolymer and thiol-yne polymer; the polymer mixture comprising at leastone region in which the first polymer has a first degree of cure and thesecond polymer has a second degree of cure that is different from thefirst degree of cure. Preferably, the cover is a second lens, plano orcoating. More preferably, the first lens is a lens blank.

A polymerizable composition comprising:

a first ene monomer and a first thiol monomer together having a firstrefractive index; and

a second ene monomer and a second thiol monomer together having a secondrefractive index;

wherein the first ene monomer is selected from the group consisting ofstyrene, divinylbenzene,

wherein the first thiol monomer is selected from the group consisting ofthiobisbenezenethiol,

Another embodiment provides a kit comprising: a first containercomprising a first monomer composition having a first refractive index,the first monomer composition comprising a first ene monomer and a firstthiol monomer; and a second container comprising a second monomercomposition having a second refractive index, the second monomercomposition comprising a second ene monomer and a second thiol monomer;wherein the difference between the first refractive index and the secondrefractive index is in the range of about 0.001 to about 0.5.

Another embodiment is a method of stabilization of refractive index inthe optical element in which the matrix polymer comprises an amount of apolymerization inhibitor that is effective to at least partially inhibitpolymerization of the monomer mixture.

These and other embodiments are described in greater detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will be readily apparent fromthe following description and from the appended drawings (not to scale),which are meant to illustrate and not to limit the invention, andwherein:

FIG. 1 is a cross-sectional view schematically illustrating a preferredprocess for making a polymer composition.

FIGS. 2 and 3 are cross-sectional views schematically illustrating apreferred lens assembly process.

FIG. 4 is a reproduction of a photograph of a photomask suitable forwriting a trefoil pattern in an optical element.

FIG. 5 shows an optical path difference (OPD) map obtained on an opticalelement.

FIG. 6 shows a plot illustrating the change in the OPD pattern as afunction of time for a trefoil written into a sandwich polymer gel.

FIG. 7 shows curing curves (dynamic range vs. time) for two lensesprepared as described in Example 29.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The term “polymer” is used herein in its usual sense and includes, e.g.,relatively large molecules built up by linking together smallermolecules, natural and synthetic polymers, pre-polymers, oligomers,crosslinked polymers, blends, interpenetrating polymer networks,homopolymers, and copolymers (including without limitation block andgraft copolymers). Likewise, the term “polymerization” is used herein inits usual sense and includes, e.g., a process of linking togethersmaller molecules to form polymers, crosslinking, oligomerization, andcopolymerization. Polymerization includes photopolymerization(polymerization induced by irradiation) and thermal photopolymerization(polymerization induced by heat and irradiation).

The term “monomer” is used herein in its usual sense and includes, e.g.,molecules that contain one or more polymerizable groups, includingmacromers. Monomers that contain more than one polymerizable group maybe referred to herein as “multifunctional.” A multifunctional monomermay be a crosslinker as described below. The terms “recurring unit” and“repeating unit” are used herein in their usual sense and include, e.g.,the structures within the polymer that correspond to the linked-togethermonomers. The term “matrix polymer” refers herein to a polymer that iscapable of functioning as a matrix, e.g., capable of including withinits interstitial spaces various molecules such as, e.g., polymers andmonomers. A matrix polymer may be crosslinked or non-crosslinked. Amatrix polymer may possess free reactive groups such as acrylate, vinyl,allyl, methacrylate, epoxy, thiol, hydroxy, etc.

A “polyester” or “ester polymer” is a polymer that contains multipleester recurring units and thus includes unsaturated polyesters. A“polystyrene” or “styrene polymer” is a polymer that contains multiplesubstituted and/or unsubstituted styrene recurring units and thusincludes functionalized styrene polymers such as poly(allyloxystyrene).A “polyacrylate” or “acrylate polymer” is a polymer that containsmultiple —(CH₂—C(R¹)(CO₂R²))— units, where R¹ represents hydrogen orC₁-C₆ alkyl, and R² represents hydrogen, C₆-C₁₂ aryl, C₆-C₁₂ halogenatedaryl, C₁-C₆ alkyl or C₁-C₆ hydroxyalkyl. An epoxy polymer is a polymerthat contains one or more epoxy groups. A “thiol-cured epoxy polymer” isa polymer formed by reacting a thiol-containing compound with an epoxypolymer. An isocyanate polymer is a polymer that contains one or moreisocyanate groups. A “thiol-cured isocyanate polymer” is a polymerformed by reacting a thiol-containing compound with an isocyanatepolymer. A “polyethyleneimine” is a polymer that contains ethylenerecurring units and imine groups. An “unsaturated” polymer is a polymercontaining one or more carbon-carbon double bonds.

An “ene” or “ene monomer” is a monomer that contains one or morecarbon-carbon double bonds. A “thiol” or “thiol monomer” is a monomerthat contains one or more sulfur-hydrogen bonds. A “thiol-ene polymer”is a polymer formed by the polymerization of an ene monomer and a thiolmonomer. An “yne” or “yne monomer” is a monomer that contains one ormore carbon-carbon triple bonds. A “thiol-yne polymer” is a polymerformed by the reaction of an yne monomer and a thiol monomer. A“crosslinking agent” is a compound that is capable of causing twomonomers to be linked to one another, or a polymer molecule to be linkedto another monomer or polymer molecule, typically by forming acrosslink. Crosslinking agents may be “crosslinkers”, e.g.,multifunctional compounds that become incorporated into the resultingcrosslinked polymer, or may be “curing agents,” e.g., catalysts orinitiators that bring about reactions between the monomers, between thepolymer molecules, between polymer molecules and crosslinkers, and/orbetween polymers and monomers to form the crosslinks. Curing agentstypically do not become incorporated into the resulting crosslinkedpolymer. Thus, a crosslinking agent may be a crosslinker, a curingagent, or a mixture thereof. A crosslinked polymer may be optionallycrosslinked to such an extent that it becomes infusible and/orinsoluble. The terms “degree of crosslinking” and “degree of cure” referto the extent of polymerization or crosslinking of a particular polymer,and can be expressed as a percentage of the difference in refractiveindex between the uncured (monomer) and fully cured versions of thatpolymer.

The term “mixture” is used herein in its usual sense to include variouscombinations of components, and thus includes polymer blends andinterpenetrating networks (including semi-interpenetrating networks). A“blend” of polymers or “polymer blend” is an intimate mixture of two ormore different polymers, e.g., a mixture of polymers that is phaseseparated on a microscopic scale. A “compatible blend” of polymers is apolymer blend that does not exhibit phase separation on a microscopicscale using visible light. An “interpenetrating polymer network” (IPN)is an intimate mixture of two or more polymers in which the polymersinterpenetrate each other and entangle to some degree. An IPN istypically made by forming and/or crosslinking one polymer in thepresence of monomers and/or another polymer.

The term “film” is used herein to refer to a material in a form having athickness that is less than its height or width. A film typically has athickness of about ten millimeters or less. A film may be free standingand/or may be hard-coated to enhance its mechanical stability, coatedonto a surface or sandwiched between other materials. For example, afilm may be formed while sandwiched between a substrate and a cover, orplaced between a substrate and cover after being formed. The substrateand/or cover may be relatively non-stick materials such as polyethyleneor fluorinated polymers that facilitate subsequent removal, or thesubstrate and/or cover may be materials (e.g., lens or lens blank) thatare incorporated into the final product, e.g., an optical element. Acomposition is considered “substantially transparent to opticalradiation” if it is suitable for use in an optical element such as alens, mirror or prism. Thus, such a composition may be colored or tintedto a degree, e.g., in the general manner of sunglasses or tinted contactlenses, and still be considered “substantially transparent to opticalradiation.”

The foregoing definitions and examples mentioned therein arenon-limiting and not mutually exclusive. Thus, for example, a compatiblepolymer blend may be an IPN and vice versa.

A preferred embodiment is a composition that comprises a matrix polymerand a monomer mixture dispersed therein. The matrix polymer ispreferably selected from the group consisting of polyester, polystyrene,polyacrylate, thiol-cured epoxy polymer, thiol-cured isocyanate polymer,and mixtures thereof. The matrix polymer may be obtained commercially ormade by methods known to those skilled in the art. Preferred matrixpolymers contain (or are prepared from polymers that contain) reactivegroups (e.g., double bonds and/or epoxy groups) that facilitatecrosslinking. Preferably, the matrix polymer is unsaturated (e.g.,contains double bonds) and/or contains epoxy groups and/or containsisocyanate groups. Crosslinking may be accomplished chemically (e.g., byreacting the matrix polymer with a crosslinker such as a thiol,preferably in the presence of a curing agent such as an amine, tincompound, phosphate compound, or mixtures thereof) or photochemically(e.g., by exposure to visible or ultraviolet radiation), optionally withheating. The amount of crosslinking agent used to crosslink the polymeris preferably selected based on the desired degree of cure andrespective curing characteristics of the matrix polymer and crosslinkingagent in a manner generally well known to those skilled in the art.

In a preferred embodiment, the matrix polymer is the product of achemical reaction between a crosslinking agent and an unsaturatedpolyester, unsaturated polystyrene, unsaturated polyacrylate, or mixturethereof. An example of a preferred unsaturated polyester is representedby the formula (I) in which n is an integer in the range of from about 2to about 5,000, preferably from about 2 to about 100.

Unsaturated polyesters encompassed by the formula (I) are availablecommercially (e.g., ATLAC 382-E from Reichhold) or may be prepared bymethods known to those skilled in the art (e.g., from bisphenol A andmaleic anhydride). The unsaturated polyester of the formula (I) ispreferably crosslinked by intermixing with a thiol, more preferably inthe presence of an amine, optionally with heating. This invention is notbound by theory, but it is believed that the thiol undergoes Michaeladdition with the fumaric acid recurring unit to bring aboutcrosslinking of the unsaturated polyester. Examples of preferred aminesuseful for crosslinking unsaturated polymers include polyethyleneimineand tetraalkyl ammonium halide. See Anthony Jacobine, “Radiation CuringPolymer Science and Technology,” Vol. 3, Ed. by J. P. Fouassier and J.F. Rabek, Elsevier Applied Science, pp. 219-268.

An example of a preferred unsaturated polystyrene is apoly(allyloxystyrene), preferably as represented by the formula (II) inwhich n is an integer in the range of from about 2 to about 5,000,preferably from about 2 to about 100.

The unsaturated polystyrene of the formula (II) is availablecommercially or may be prepared by methods known to those skilled in theart. Unsaturated polystyrenes are preferably crosslinked by exposure tovisible or ultraviolet radiation, optionally with heating. Thisinvention is not bound by theory, but it is believed that theunsaturated groups (e.g., allyloxy groups) in the presence of a suitablecuring agent (e.g., an initiator) react with one another or with thiolsto bring about crosslinking of the unsaturated polystyrene.

In a preferred embodiment, the matrix polymer is an epoxy polymer, anisocyanate polymer, or a mixture thereof, more preferably a thiol-curedepoxy polymer, thiol-cured isocyanate polymer, or mixture thereof. Anexample of a preferred epoxy polymer is represented by the formula (III)in which n is an integer in the range of from about 2 to about 5,000,preferably from about 2 to about 100.

The epoxy polymer of the formula (III) is available commercially or maybe prepared by methods known to those skilled in the art. A wide varietyof epoxy polymers may be prepared by the reaction of epoxy monomers withcomonomers (e.g., amines, alcohols, carboxylic acids and/or thiols) in amanner generally known to those skilled in the art. Examples ofpreferred epoxy monomers and polymers include those represented by thefollowing structures in which n is an integer in the range of from about2 to about 5000, preferably from about 2 to about 100:

Epoxy polymers are preferably crosslinked by intermixing with a thiolmonomer (crosslinker) and an amine curing agent, optionally withheating. Thiol-cured epoxy polymers are preferred.

An example of a preferred isocyanate polymer is represented by theformula (IV), wherein each X is individually selected from the groupconsisting of O, NH and S; wherein R₁ and R₂ are each individuallyselected from the group consisting of C₂-C₁₈ aliphatic and C₆-C₁₈aromatic; and wherein m is an integer in the range of from about 1 toabout 5,000, preferably from about 1 to about 100.

The isocyanate polymer of the formula (IV) is available commercially ormay be prepared by methods known to those skilled in the art. Examplesof preferred commercially available isocyanate polymers include Desmodur3300AR3600 (homopolymer of hexamethylene diisocyanate, CAS 28182-81-2,available from Bayer). A wide variety of isocyanate polymers may beprepared by the reaction of isocyanate monomers with comonomers (e.g.,alcohols, amines and/or thiols) in a manner generally known to thoseskilled in the art. Examples of preferred commercially availableisocyanate monomers (Mondur, from Bayer) include those represented bythe following structures:

Isocyanate polymers are preferably crosslinked by intermixing with acrosslinking agent (e.g., thiol, amine, alcohol, tin compound, and/orphosphate compound), optionally with heating. Thiol-cured isocyanatepolymers are preferred. Preferably, the thiol crosslinker is a thiolmonomer as described elsewhere herein.

The monomer mixture dispersed within the matrix polymer preferablycomprises monomers that undergo step-growth polymerization, morepreferably comprises monomers that undergo radiation-initiated stepgrowth polymerization. For example, a preferred monomer mixturecomprises a thiol monomer and at least one second monomer. The secondmonomer is preferably an ene monomer, an yne monomer, or a mixturethereof, more preferably a multifunctional ene monomer. The thiolmonomer is preferably a multifunctional thiol monomer. Non-limitingexamples of preferred thiol monomers include those represented by thefollowing structures:

The structures of additional examples of preferred thiol monomers areshown in Table 1, in which n, m, x, y, and z are each individually inthe range of about 2 to about 5,000, preferably 2 to 100. A wide varietyof thiol monomers may be purchased commercially or prepared by methodsknown to those skilled in the art.

The second monomer is preferably an ene monomer, an yne monomer, or amixture thereof. The second monomer is preferably a multifunctionalmonomer. Non-limiting examples of preferred ene monomers include thoserepresented by the following structures:

The structures of additional examples of preferred second monomers areshown in Table 2, in which n, m, x, y, and z are each individually inthe range of about 2 to about 5000, preferably from about 2 to about100. A particularly preferred type of ene monomer is represented bystructure (V), in which n is an integer, preferably in the range ofabout 1 to about 6. A preferred method for preparing the ene monomerrepresented by the structure (V) in which n=1 is described in theExamples below.

Polymer compositions that comprise a matrix polymer and a monomermixture dispersed therein preferably further comprise a curing agent(preferably a photoinitiator) and optionally one or more additives suchas a polymerization inhibitor, antioxidant, photochromic dye, and/orUV-absorber. Such additives are commercially available. Photoinitiatorsmay be present in the polymer composition as the residue of a priorphotoinitiated polymerization (e.g., for the preparation of the matrixpolymer) or may be included for other purposes, preferably forinitiating polymerization of the monomer mixture. The amount and type ofphotoinitiator are preferably selected to produce the desired polymer,using selection criteria generally known to those skilled in the art.The compound 1-hydroxy-cyclohexyl-phenyl-ketone (available commerciallyfrom Ciba under the trade name Irgacure™ 184) is an example of apreferred photoinitiator. Other preferred photoinitiators includebenzoin, Irgacure™ 500 (50% 1-hydroxy-cyclohexyl-phenyl-ketone+50%benzophenone), Irgacure™ 651 (2,2-dimethoxy-1,2-diphenylethan-1-one),Irgacure™ 819 (bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide), andIrgacure™ 2959(1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one).Examples of preferred polymerization inhibitors include N-PAL (N-nitrosoN-phenylhydroxylamine aluminium salt) and MEHQ (4-methoxyphenol).Examples of preferred UV-absorbers include Tinuvin® 327(2,4-di-tert-butyl-6-(5-chlorobenzotriazol-2-yl) phenol), and Tinuvin®144 (bis(1,2,2,6,6-pentamethyl-4-piperidinyl)(3,5-di-(tert)-butyl-4-hydroxybenzyl)butylpropanedioate). Examples ofpreferred antioxidants include TTIC(tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate), and IRGANOX 1010(tetrakis-(methylene-(3,5-di-tert-butyl-4-hydrocinnamate)methane).Examples of photochromic dyes include spiro-naphthoxazines andnaphthopyrans (e.g., Reversacol™ dyes from James Robinson, UK) and thosedisclosed in PCT WO 02091030, which is hereby incorporated by referenceand particularly for the purpose of describing photochromic dyes.

Polymer compositions that comprise a matrix polymer and a monomermixture dispersed therein may be prepared by intermixing, in any order,the matrix polymer, the thiol monomer and the second monomer.Preferably, intermixing is conducted by forming and/or crosslinking thematrix polymer in the presence of the thiol monomer and second monomer.For example, in a preferred embodiment, an unsaturated polyester matrixpolymer is intermixed with a photoinitiator, a thiol monomer, an enemonomer, and optionally a crosslinking agent (e.g., an amine) to form acomposition comprising an unsaturated polyester matrix polymer and amonomer mixture (thiol and ene) dispersed therein. In anotherembodiment, that composition is heated and/or irradiated to at leastpartially crosslink the unsaturated polyester, thereby forming acomposition comprising a thiol-cured polyester, a remaining thiolmonomer and the ene monomer. Preferably, the amount of remaining thiolmonomer is sufficient to react with the ene monomer. It will beunderstood by those skilled in the art that a portion of the ene monomermay also react with pendant thiol groups tethered on unsaturatedpolyester and become part of the thiol-cured polyester. In an additionalembodiment, discussed below, either of these compositions (eachcomprising a matrix polymer and a monomer mixture dispersed therein) isirradiated to at least partially polymerize the thiol and ene monomersto form a thiol-ene polymer, thereby forming a mixture comprised of thematrix polymer (e.g., polyester) and the thiol-ene polymer. The relativeamounts of ene and thiol monomers in the polymerizable composition arepreferably such that the number of ene functional groups is about equalto the number of thiol functional groups.

FIG. 1 schematically illustrates a preferred process for making apolymer composition that comprises a matrix polymer and a monomermixture dispersed therein. In the illustrated embodiment, the matrixpolymer is a polyester and the monomer mixture comprises a thiol monomerand an ene monomer. It will be understood that other matrix polymers andmonomers may be used in the process described herein in connection withFIG. 1, including those described herein. In addition, variations of thepreferred process may be practiced, using the knowledge of one skilledin the art in light of the teachings provided herein.

The composition 310 illustrated in FIG. 1 contains 13 parts of anunsaturated polyester represented by the formula (I), 10 parts of an enemonomer (pentaerythritol triallyl ether), 21 parts of a thiol monomer(trimethylolpropane tri(3-mercaptoproprionate)), 1.1 parts of an amine(polyethyleneimine), and 0.075 parts of a photoinitiator Irgacure™ 184(all parts herein are by weight, unless otherwise stated). Thecomposition 310 is degassed under vacuum and sandwiched between a glasscover 315 and a glass substrate 320, then crosslinked by heating 325 forabout 40 minutes at a temperature of about 65° C. to 75° C. Longer orshorter periods of heating may be employed for crosslinking otherpolymers. The heating 325 results in the crosslinking of the unsaturatedpolyester with the thiol in the composition 310, thereby forming acomposition 330 that contains a thiol-cured polyester having free thiolgroups, the ene monomer, the remaining thiol monomer, thephotoinitiator, and (typically) a small amount of residual amine (e.g.,amine not consumed by crosslinking). It is understood that small amountsof the ene monomer, thiol monomer, and/or photoinitiator may be consumed(e.g., incorporated into the crosslinked polyester in the composition330) during the crosslinking.

The glass cover 315 and substrate 320 allow the composition 330 to beprepared in the form of a uniform film having a controlled thickness.For example, spacers may be optionally placed between the plates to forma film having a desired thickness. One or both of the cover 315 andsubstrate 320 may be flat or curved plates that may be used to form afilm having a desired topology. Preferably, the covers are substantiallytransparent to optical radiation. Examples of suitable cover andsubstrate materials include optically transparent materials having arefractive index in the range of about 1.5 to about 1.74, such as glassand plastic, preferably polycarbonate, Finalite™ (Sola), MR-8 polymer(Mitsui), and diethylene glycol bis(allylcarbonate) polymer (CR-39) (PPGIndustries). The cover may be a protective coating. Preferably, one orboth of the covers is a lens, plano lens, or lens blank.

It is also understood that the glass cover 315 and substrate 320 areoptional. For example, the composition 310 may be cast onto a substrateand crosslinked to form a free-standing film, e.g., a film havingsufficient mechanical strength to allow it to be peeled from thesubstrate, without using a cover. Preferably, the physical form of thecomposition 330 is a gel, e.g., a gel in film form. To facilitatepeeling the filmy gel from the surface, it is preferable to treat thesurface of the substrate with a release agent prior to applying thecomposition 310, and/or to use a hard coated UV-clear CR-39 substrate.The peeled film may be hard coated to enhance its mechanical stability.

Polymer compositions that comprise a matrix polymer and a monomermixture dispersed therein may be used to make compositions that comprisea first polymer and a second polymer, the second polymer being formed bypolymerization of the monomer mixture. For example, as illustrated inFIG. 1, the composition 330, sandwiched between the glass cover 315 andsubstrate 320, is exposed to radiation 340 (preferably with heating),thereby activating the photoinitiator and polymerizing 345 the monomersdispersed within the composition 330 to form a thiol-ene polymer in thepresence of the crosslinked polyester. A photomask 347 is used tocontrol the amount of radiation received at different points in thecomposition 330. The photomask 347 may comprise regions 342 that areessentially opaque to the radiation, regions 343 that are essentiallytransparent to the radiation, and regions such as the region 344 thattransmit a portion of the radiation. The resulting composition 350 thuscontains the crosslinked polyester, the thiol-ene polymer (e.g., inregions 352, 353 exposed to the radiation 340), the partiallypolymerized thiol-ene (e.g., in region 352, exposed to the radiation340) and (in some cases) largely un-polymerized thiol monomer and enemonomer (e.g., in regions 351 not exposed to radiation 340).

It will be understood that the degree of cure of the thiol-ene polymerin any particular region will be related to the amount of radiationtransmitted by the photomask 347 to that particular region. Thus, thedegree of cure of the thiol-ene polymer may be controlled by thephotomask, allowing various patterns of cure to be written into thecomposition 350. For example, in the embodiment illustrated in FIG. 1,the cure pattern in the composition 350 results from the varying degreesof cure in the regions 351, 352, 353. Additional regions of thephotomask with additional variations in their transmissibility may beused. It will be understood that a relatively simple cure pattern isshown in FIG. 1 for the purposes of illustration, and that much morecomplex cure patterns may be obtained. For example, a complex patternmay be created in a photomask using well known photolithographictechniques, and that photomask may be used to create a correspondinglycomplex cure pattern in the polymer composition. Other digital masksystems such as Digital Light Projector (DLP) along with a UV-lightsource or UV-Vertical Cavity Surface Emitting Laser (UV-VSCEL) or laser(e.g., triple YAG) or bundled UV-LED may be used.

Preferably, composition 350 is a polymer blend, more preferably an IPNor compatible blend. The polymerization of the monomers in thecomposition 330 may be in one or multiple stages, e.g., by exposure to asingle dose of radiation or multiple doses. Likewise, the monomers inthe various regions 351, 352, 353 of the composition 350 may bepolymerized to the same degree or different degrees, and/or at the sameor different times. Thus, for example, the photomask 347 may be used asillustrated in FIG. 1 to simultaneously irradiate various regions of thecomposition 330 to produce a composition in which the thiol-ene polymeris polymerized to varying degrees in the various regions 351, 352, 353.The same or similar effect may be achieved by sequentially irradiatingvarious regions, e.g., by varying the intensity of a scanning lightsource (e.g., a laser) across the composition 330. Additional monomer(s)may be added at any stage of the process. For example, monomer(s) may bediffused into the composition 330 and/or the composition 350, then laterpolymerized, as illustrated in Example 16 below.

The crosslinking of the matrix polymer and the polymerization of themonomers may be conducted simultaneously or sequentially (in eitherorder), preferably sequentially, and the degree of polymerization orcrosslinking of each polymer may be controlled independently, so as tobe different (or the same) from place to place within the composition.Preferably, the matrix polymer is crosslinked prior to polymerization ofthe monomers. For example, the composition 350 illustrated in FIG. 1contains a crosslinked polyester in which the degree of crosslinking issubstantially constant throughout the composition, and a thiol-enepolymer having degrees of polymerization in the various regions 351,352, 353 that are different from each other.

In many end-use applications, e.g., lenses, it may be undesirable forthe composition 350 to contain slightly polymerized or un-polymerizedmaterials. In a preferred embodiment, the monomers in a substantialportion of the regions are at least partially polymerized, therebyadvantageously reducing the residual monomer content and increasing thestability of the composition. For example, in FIG. 1 the entirecomposition 350 is exposed to radiation 355, thereby at least partiallypolymerizing the thiol and ene monomers 360 throughout the composition350 to produce the polymer composition 365. Preferably, the degree ofcure (polymerization) of the thiol and ene monomers is controlled sothat the cure pattern previously written into the composition 350 islargely preserved. Such control may be exercised by, e.g., exposing thecomposition 350 to radiation in a manner that increases the degree ofcure of the entire composition 350 by approximately the same amount. Forexample, if a region 352 of the composition 350 has been previouslycured to a degree of cure of about 60% and another region 353 has beencured to a degree of cure of about 20%, the difference in degree of curebetween the two regions 352, 353 is about 40%. This difference in degreeof cure may be largely preserved (and thus the difference in physicalproperties, e.g., refractive index, may be largely preserved) byexposing both regions 352, 353 to an amount of radiation that increasesthe degree of cure to 70% and 30% in the resulting two regions 362, 363,respectively.

For compositions comprising a mixture that contains a first polymer anda second polymer (e.g., the compositions 350, 365), the relative amountsof first and second polymer are preferably in the range of about0.01:9.99 to about 9.99:0.01, more preferably about 3:7 to about 7:3, byweight. The relative amounts of first and second polymer may becontrolled by making the precursor composition (e.g., the composition330) with the corresponding amounts of matrix polymer and monomers,and/or adding additional monomers and/or polymers during the process ofmaking the desired composition.

Those skilled in the art, in light of the teachings provided herein,will understand that the physical properties of the first and secondpolymers may each be independently controlled, both temporally andspatially. Thus, for example, a preferred embodiment provides acomposition comprising a mixture that comprises a first polymer and asecond polymer, in which the mixture comprises at least one region inwhich the first polymer has a first degree of cure and the secondpolymer has a second degree of cure that is different from the firstdegree of cure. For example, in FIG. 1, the degree of cure of the firstpolymer (crosslinked polyester matrix) in the region 353 of thecomposition 350 may be the same as the degree of cure of the secondpolymer (thiol-ene polymer) in that region, but preferably the degreesof cure are different. In addition, the composition preferably comprisesa second region in which the two degrees of cure are also different,both from each other and, optionally, from the degrees of cure in thefirst region. For example, in the composition 350, the degree of cure ofthe thiol-ene polymer in the region 353 is different than the degree ofcure of the crosslinked polyester matrix in the region 353, anddifferent from the degree of cure of the thiol-ene polymer in the region352. In a preferred embodiment, the first degree of cure is in the rangeof about 50% to about 100%, and/or the second degree of cure is in therange of about 1% to about 100%, based on the difference in refractiveindex between the uncured and cured first polymer as described below.More preferably, the first polymer is selected from the group consistingof polyester, polystyrene, polyacrylate, thiol-cured epoxy polymer,thiol-cured isocyanate polymer, and mixtures thereof, and/or the secondpolymer is selected from the group consisting of thiol-ene polymer andthiol-yne polymer.

Preferably, the differences in degree of cure in various regions of thecomposition result in differences in optical properties. Thus,measurement of an optical property often provides a convenient way toexpress the degree of cure. Refractive index measurements have beenfound to be particularly convenient for this purpose, because therefractive index of a monomer or monomer mixture is generally differentfrom the corresponding polymer formed from that monomer or monomermixture. Therefore, the degree of cure can be expressed in percentageterms, based on the difference in refractive index between the uncuredand cured polymer. For example, a hypothetical monomer has a refractiveindex of 1.5 and the polymer formed from that monomer has a refractiveindex of 1.6. The degree of cure of a partially polymerized compositionformed from that monomer would be considered 10% for a refractive indexof 1.51, 40% for a refractive index of 1.54, 80% for a refractive indexof 1.58, etc. Another method to determine the degree of cure is tomeasure the optical path difference (OPD) by Zygo Interferometry.

Compositions described herein (comprising a first matrix polymer and amonomer mixture or comprising a first polymer and a second polymer)preferably have a refractive index in the range of about 1.5 to about1.74. For compositions having two or more refractive indices (e.g.,compositions in which the refractive index varies from place to placewithin the composition), a composition is considered to have arefractive index in the range of about 1.5 to about 1.74 if any one ofthe various refractive indices is in the range of about 1.5 to about1.74. Compositions having two or more regions of refractive indices maybe prepared by controlling the degree of cure at various points withinthe composition using, e.g., a photomask, digital mask (DLP) or scanninglaser as discussed above. Preferably, the photomask permits variousdegrees of cure between full cure and no cure, e.g., transmits variousamounts of radiation as a function of position within the photomask,thereby controlling the intensity of transmitted radiation (and degreeof cure) in any particular region of the composition. Likewise, ascanning laser may be used to selectively cure the polymer in a firstregion of the composition to the extent desired in that first region,then scanned to a second region to selectively cure the polymer in thesecond region to a degree that is the same or different (as desired)than the degree of cure in the first region, then scanned to a thirdregion to selectively cure the polymer in the third region to a degreethat is the same or different (as desired) than the degree of cure inthe first and/or second regions, etc.

It has been found that the stability of compositions containing multipleregions having differing degrees of cure may be influenced by variousfactors, including gravity (e.g., dense regions tend to sink), diffusion(e.g., monomers tend to diffuse faster than higher molecular weightcomponents) and polymerization (e.g., slow thermal polymerization ofmonomers and/or partially cured regions at ambient temperature). Inpreferred embodiments, one or more such stability issues are addressed,and compositions having improved stability are provided, e.g., asdemonstrated in the examples below. Preferred compositions comprise apolymerization inhibitor that is present in an amount effective to atleast partially inhibit polymerization of monomers and/or partiallycured regions of the composition.

In some cases the procurement of various monomers, polymers and/oradditives useful for making an optical element may be inconvenientand/or costly. A preferred embodiment is directed to a kit thatcomprises at least one container and one or more of the components usedto make the compositions described herein. For example, a preferred kitcomprises at least one container, a matrix polymer, a thiol monomer, anda second monomer. Preferably, the matrix polymer is a polyester, apolystyrene, a polyacrylate, an epoxy polymer, an isocyanate polymer, ora mixture thereof. Preferably, the second monomer is an ene monomer, ynemonomer or mixture thereof. In a preferred embodiment, a first containercomprises a thiol monomer, and a second container comprises a secondmonomer (more preferably, selected from the group consisting of enemonomer and yne monomer) and a matrix polymer (more preferably, selectedfrom the group consisting of polyester, polystyrene, polyacrylate, epoxypolymer, isocyanate polymer, and mixtures thereof). Preferred kitsfurther comprise one or more additives selected from the groupconsisting of photoinitiator, polymerization inhibitor, antioxidant,photochromic dye, and/or UV-absorber. Preferably, at least one materialselected from the group consisting of the matrix polymer, the thiolmonomer and the second monomer, has a refractive index in the range ofabout 1.5 to about 1.74. More preferably, the matrix polymer, the thiolmonomer and the second monomer each have a refractive index in the rangeof about 1.5 to about 1.74.

The compositions described herein may be used in a number ofapplications. For example, preferred compositions are substantiallytransparent to optical radiation, and thus are useful as opticalelements, e.g., eyeglass lenses, intraocular lenses, contact lenses, andlenses used in various pieces of optical equipment. The methodsdescribed herein enable the production of optical elements in which theindex of refraction at any particular point within the element can becontrolled. Such optical elements are useful in, for example, theproduction of optical elements that correct higher-order aberrations ofthe human eye, see, e.g., U.S. Pat. No. 6,712,466, and co-pending U.S.application Ser. No. 10/935,798 entitled “Method of Manufacturing anOptical Lens”), filed Sep. 7, 2004, both of which are herebyincorporated by reference in their entireties.

Additional preferred embodiments provide polymerizable compositionsuseful for making optical elements. These polymerizable compositions areparticularly useful for fabricating optical elements using the methodsdescribed in U.S. patent application Ser. No. 10/253,956, published asU.S. patent application Publication No. 2004-008319 A1, both of whichare hereby incorporated by reference in their entireties. U.S. patentapplication Publication No. 2004-0008319 A1 (“the '8319 publication”)discloses, inter alia, techniques for making optical elements usingmicro-jet printing methods to precisely control the type, position andamount of polymer deposited onto a substrate. In preferred embodiments,the proportions of two or more different polymer compositions are variedover the course of the deposition process to deposit adjoining polymerpixels in the form of a film on the substrate surface. The opticalproperties of each adjoining polymer pixel can be selected to provide apredetermined optical property, including a specific value of index ofrefraction. Preferably, the film has a radially non-monotonic refractiveindex profile and/or an angularly non-monotonic refractive indexprofile.

As described in the '8319 publication, preferred methods for makingoptical elements involve the projection of two or more polymercompositions onto pre-selected locations on a substrate. The term“polymer composition,” as used in the '8319 publication, is a broad termthat refers to a composition that comprises a polymer, and the term“polymer” includes all forms of polymer and their precursors, includingpolymerizable compositions such as pre-polymers.

Polymerizable compositions have now been discovered that areparticularly well-suited for use in the methods described in the '8319publication, although they are useful for other applications as well.Preferred polymerizable compositions comprise a first ene monomer and afirst thiol monomer together having a first refractive index; and asecond ene monomer and a second thiol monomer together having a secondrefractive index; the difference between the first refractive index andthe second refractive index being in the range of about 0.001 to about0.5, preferably in the range of about 0.001 to about 0.1. The monomersmay be intermixed in any order to form the polymerizable composition.The polymerizable compositions are preferably made by preparing a highindex composition comprising the first ene monomer and a first thiolmonomer; preparing a low index composition comprising second ene monomerand a second thiol monomer, and may involve intermixing the high indexcomposition and the low index composition to form the polymerizablecomposition. The refractive indices of each of the monomer pairs (e.g.,the first refractive index of the first ene monomer and the first thiolmonomer together) are measured apart from the polymerizable composition.To determine the refractive index of the ene monomer and thiol monomerapart from the polymerizable composition, a test sample is preparedwhich contains the ene monomer and thiol monomer together in the samerelative proportions as in the polymerizable composition. The refractiveindex of the test sample is then determined at 25° C. Those skilled inthe art will recognize that various mixtures of the components arethemselves polymerizable compositions. For example, the first enemonomer and a first thiol monomer together form a polymerizablecomposition, and likewise the second ene monomer and the second thiolmonomer together form a second polymerizable composition.

The high index composition and the low index composition are preferablyintermixed by the methods described in the '8319 publication. Forexample, FIG. 1A of the '8319 publication illustrates a preferredembodiment in which two polymer compositions are projected onto asubstrate using a spray unit 100 that is controlled by a computerizedcontroller 105, the spray unit 100 comprising a first spray head 110 anda second spray head 115 (reference numbers refer to those used in the'8319 publication). Preferably, the first spray head 110 contains or ischarged with a high index composition, and the second spray head 115contains or is charged with a low index composition. Intermixing of thehigh and low index compositions to form a polymerizable composition maythen be conducted as described in the '8319 publication, e.g., byprojecting a first polymer droplet from the first spray head 110 onto apre-selected location on the substrate 120 to form a first depositedpolymer droplet 125, projecting a second polymer droplet 130 from thesecond spray head 115 in close proximity to the first deposited polymerdroplet 125, and forming a first polymer pixel 135 by mixing the firstdeposited polymer droplet 125 and the second polymer droplet 130. Thus,in this embodiment, the first polymer pixel 135 comprises thepolymerizable composition formed from the high index composition(comprising the first ene monomer and the first thiol monomer togetherhaving a first refractive index, as measured apart from thepolymerizable composition) and the low index composition (comprising thesecond ene monomer and the second thiol monomer together having a secondrefractive index, as measured apart from the polymerizable composition).Preferably, the difference between the first refractive index and thesecond refractive index is in the range of about 0.001 to about 0.5,preferably in the range of about 0.001 to about 0.1. The polymerizablecompositions may also be formed or used by other methods described inthe '8319 publication.

The refractive index of the polymerizable composition may be varied overa broad range by varying the relative amounts of the high indexcomposition and the low index composition, and by appropriate selectionof the ene and thiol monomers themselves. The ratio of high indexcomposition to low index composition in the polymerizable compositionmay vary over a broad range of from about 0:100 to about 100:0.Preferably, the ratio is selected by considering the refractive index ofthe individual components, using routine experimentation to confirm thatthe resulting mixture provides the desired refractive index afterpolymerization. Preferably, the relative amounts of ene and thiolmonomers are selected such that subsequent polymerization forms apolymer having the desired physical properties, e.g., mechanical andoptical properties. More preferably, the relative amounts of ene andthiol monomers in the polymerizable composition are such that the numberof ene functional groups is about equal to the number of thiol groups.

A wide variety of ene and thiol monomers are useful for makingpolymerizable compositions. The thiol and ene and yne monomers shown inTables 1 and 2 are preferred. The refractive indices of preferred highand low index compositions are described in the Examples below. Therefractive indices of other high and low index compositions may bedetermined by routine experimentation. In any particular polymerizablecomposition, the first ene monomer may be the same as the second enemonomer, or the first thiol monomer may be the same as the second thiolmonomer, so long as the first ene monomer and the first thiol monomertogether have a first refractive index, as measured apart from thepolymerizable composition, and the second ene monomer and the secondthiol monomer together have a second refractive index, also as measuredapart from the polymerizable composition, such that the differencebetween the first refractive index and the second refractive index is inthe range of about 0.001 to about 0.5, more preferably in the range ofabout 0.001 to about 0.1. Preferably, the first ene monomer is selectedfrom the group consisting of styrene, divinylbenzene,

Preferably, the first thiol monomer and the second thiol monomer in thepolymerizable composition are selected from the group consisting ofthiobisbenezenethiol,

Preferably, the second ene monomer is:

The polymerizable composition may further comprise one or more additivessuch as solvents, surfactants, crosslinking agents, polymerizationinhibitors, polymerization initiators, colorants, flow control agents,and/or stabilizers. Preferably, the polymerizable composition comprisesone or more additives selected from the group consisting ofpolymerization initiator (e.g., photoinitiator, thermal initiator),polymerization inhibitor, antioxidant, photochromic dye, andUV-absorber.

In preferred embodiments the components of the polymerizable compositionare provided in the form of a kit. A preferred kit comprises a firstcontainer comprising a high index composition having a first refractiveindex, the high index composition comprising a first ene monomer and afirst thiol monomer; and a second container comprising a low indexcomposition having a second refractive index, the low index compositioncomprising a second ene monomer and a second thiol monomer, thedifference between the first refractive index and the second refractiveindex preferably being in the range of about 0.001 to about 0.5, morepreferably in the range of about 0.001 to about 0.1. Thiol and enemonomers useful in the kit are described above. The containers mayfurther comprise one or more additives such as crosslinking agents,polymerization inhibitors, polymerization initiators, colorants, flowcontrol agents, and/or stabilizers as described above. The size, shapeand configuration of the containers may be varied as needed to provide aconvenient source of the components. For example, the kit may be in theform of a cartridge adapted for use in a polymer projection depositionsystem as described in the '8319 publication.

TABLE 1 No. Thiol Monomers 1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

TABLE 2 No. Ene and Yne Monomers 1

2

3

4

5

6

7

8

9

10

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

 

50

 

51

52

53

54

EXAMPLES

Materials: Starting materials were commercially available.Pentaerythritol triallyl ether (70% triallyl) (ene monomer) andtrimethylolpropane tris(3-mercaptopropionate) (thiol monomer) wereobtained from Aldrich. Copolymer of Bisphenol A and fumaric acid (ATLAC382-E, (unsaturated polyester) was obtained from Reichhold. The amine(1838-L 3M Scotch™ Weld (Part A)) was obtained from R. S. Hughes.Irgacure™ 184 (photoinitiator) was obtained from Ciba. N-PAL(polymerization inhibitor) was obtained from Albemarle. ATLAC wasdissolved in acetone, filtered through a 2.5μ filter and stored inacetone and used as the acetone solution of ATLAC. Poly[(phenyl glycidylether)-co-formaldehyde], an epoxy polymer represented by the formula(III), and polyethyleneimine were purchased from Aldrich. DiallyletherBisphenol A was obtained from Bimax. Tetrabutyl ammonium bromide wasobtained from Aldrich. Acetone, HPLC grade, was obtained from FisherScientific.

Example 1

A kit having Parts I and II was made as follows:

Part I: In a labeled 100 mL bottle, 6.000 g of pentaerythritol triallylether (70% triallyl), 13.000 g of trimethylolpropanetris(3-mercaptopropionate), 13.000 g of ATLAC (previously dissolved inacetone, filtered through a 2.5μ filter, and dried), 0.0088 g N-PAL and0.044 g of Irgacure™ 184 were weighed. Using a stirrer bar and amagnetic stirrer, the ingredients was stirred for about 10 minutes togive a homogenous mixture. The mixture was rotary evaporated at 50° C.for 1-2 hours to evaporate all acetone.

Part II: In another labeled 30 mL amber vial, 4.000 g of pentaerythritoltriallyl ether (70% triallyl), 8.000 g of trimethylolpropanetris(3-mercaptopropionate), and 0.528 g of amine (1838-L 3M Scotch™ Weld(Part A)) were weighed. Using a stirrer bar and a magnetic stirrer, theformulation was stirred for about 10 minutes to give a homogenousmixture.

Example 2

A portion of Parts I and II (from the kit of Example 1) were mixed in aratio of 2.53:1, respectively. The Part I composition was weighedcarefully in a 100 mL beaker. Based on the amount of Part I formulation,the calculated amount of Part II was added into the same beaker. The twocompositions were first mixed thoroughly by hand using a glass stirrer(glass was found to work better than metal), followed by mixing using amagnetic stirrer to form a mixture, then used immediately as describedin Example 3.

Example 3

The mixture of Example 2 was transferred to a glass plate equipped witha wire spacer. The mixture on the plate was degassed to remove trappedair. A thin glass plate was carefully placed over the glass plate andthe plates were pressed firmly together, with the degassed mixturesandwiched between. The sandwiched mixture was cured by exposing it toultraviolet light using a UV lamp (EXFO intensity=16.6 mW/cm²) for 5minutes. The difference in the refractive index between the sandwichedmixture and the cured film was measured to be 0.024.

Example 4

The mixture of Example 2 was transferred to a glass plate equipped witha wire spacer. The mixture on the plate was degassed to remove trappedair. A thin glass plate was carefully placed over the glass plate andthe plates were pressed firmly together, with the degassed mixturesandwiched between. The sandwiched mixture was maintained at about 60°C. for about 40 minutes to form a sandwiched gel. The gel comprised athiol-cured polyester polymer having pentaerythritol triallyl ether (70%triallyl), trimethylolpropane tris(3-mercaptopropionate) dispersedtherein. The sandwiched gel was masked and the central portion of thegel was exposed to ultraviolet radiation (EXFO intensity=16.6 mW/cm²)for about 5 minutes at about 80° C. to polymerize the ene and thiolmonomers, thereby forming a mixture of a thiol-ene polymer and acrosslinked polyester in the exposed region. The difference in therefractive index between the masked and unmasked regions was measured tobe 0.0181.

Example 5

The mask was removed from the sandwiched gel of Example 4 and the entiresandwiched gel between the two plates was exposed to ultravioletradiation (EXFO intensity=4.8 mW/cm²) at room temperature for about 2minutes, thereby partially polymerizing the thiol and ene monomers inthe area previously under the mask. The refractive index differencebetween the previously masked region and the unmasked region was 0.014.This period of exposure was found to provide increased stability of therefractive index difference between the masked and unmasked regions.

Example 6

Synthesis of 1,1,1tris(4-allyloxy-phenyl)ethane: In a 500 mL threeneck-round bottom flask equipped with condenser, magnetic stirring bar,dropping funnel, and Argon inlet, 15.00 g (49 mmol) of1,1,1tris(4-hydroxy-phenyl)ethane was dissolved in a 1:1 mixture ofmethylene chloride and tetrahydrofuran. To this mixture, a solution ofsodium hydroxide 10.70 g (267 mmol) dissolved in 60 mL of distilledwater was added while vigorously stirring. Allyl bromide, 33.36 g (276mmol) was added followed by 2.5 g (5.96 mmol)tetraphenylphosphoniumbromide catalyst. The reaction mixture was leftunder positive pressure of Argon while stirring at room temperature. Thereaction was monitored by TLC and stopped after 36 hours. The reactionmixture was transferred into separatory funnel and the product wasextracted twice with 200 mL of methylene chloride. The organic layerswere combined and extensively washed several times with distilled water.The organic extract was dried over anhydrous magnesium sulfate andfiltered using Whatman filter paper. To this filtrate, activatedcharcoal was added and the mixture was stirred for 12 h. The charcoalwas filtered and the solvent was evaporated using rotary evaporator. Theresulting viscous compound was purified through column chromatographyusing silica as stationary phase and methylene chloride as an eluent.The solvent was removed using rotary evaporator to yield 14.50 g (70%)of clear, colorless, viscous liquid of1,1,1tris(4-allyloxy-phenyl)ethane. ¹H NMR and IR spectra wereconsistent with 1,1,1tris(4-allyloxy-phenyl)ethane. ¹H NMR (CDCl₃): 4.58(m, CH_(2O), 6 H), 2.17 (s, —CH₃), 5.2 (m, ═CH2, 6 H), 6.1 (m, ═CH, 3H), 6.81 (dd, 6 aromatic H ortho to OR, 7.03 (dd, 6 aromatic H meta toOR). IR (NaCl): Major bands at 1293 cm⁻¹ (aromatic ether), 2912 cm⁻¹(aliphatic hydrocarbon), and 1648 cm⁻¹ (unsaturated hydrocarbon).

Example 7

A kit having Parts I and II was made as follows:

Part 1: In a labeled 100 mL bottle, 10.00 g of poly[(phenyl glycidylether)-co-formaldehyde], 10.89 g of trimethylolpropanetris(3-mercaptopropionate), 2.30 g of pentaerythritol triallyl ether,0.0056 g N-PAL, and 0.0281 g of Irgacure™ 184 were weighed. Acetone wasadded to dissolve the ingredients. Using a stirrer bar and a magneticstirrer, the ingredients were stirred for about 10 minutes to give ahomogenous mixture. The mixture was rotary evaporated at 50° C. for 1-2hours to evaporate all acetone.

Part II: In another labeled 30 mL amber vial, 2.3689 g ofpentaerythritol triallyl ether, 2.5782 g of trimethylolpropanetris(3-mercaptopropionate), and 0.7034 g of polyethyleneimine wereweighed. Using a stirrer bar and a magnetic stirrer, the formulation wasstirred for about 10 minutes with gentle heating to give a homogenousmixture.

Example 8

A portion of Parts I and II (from the kit of Example 7) were mixed in aratio of 4.10:1, respectively. The Part I composition was weighedcarefully in a 100 mL beaker. Based on the amount of Part I formulation,the calculated amount of Part II was added into the same beaker. The twocompositions were first mixed thoroughly by hand using a glass stirrer(glass was found to work better than metal), followed by mixing using amagnetic stirrer to form a mixture having a refractive index of 1.5316,then used immediately as described in Example 9.

Example 9

The mixture of Example 8 was transferred to a glass slide (1 mm thick)equipped with a spacer (20 mil diameter wire around the edges of theslide). The mixture on the slide was degassed to remove trapped air.Another glass slide was carefully placed over the first glass slide, andthe plates were pressed firmly together with the degassed mixturesandwiched between. The sandwiched mixture was maintained at about 65°C. for about 5.5 hours to form a sandwiched gel. The gel comprised acrosslinked epoxy polymer having pentaerythritol triallyl ether andtrimethylolpropane tris(3-mercaptopropionate) dispersed therein, andhaving a refractive index of 1.5550.

Example 10

The sandwiched gel made in Example 9 was masked and the central portionof the gel was exposed to ultraviolet radiation (EXFO intensity=100mW/cm²) for about 10 minutes at about 90° C. to polymerize the ene andthiol monomers, thereby forming a mixture of a thiol-ene polymer and acrosslinked epoxy in the exposed region. The central irradiated regionhad a refractive index of 1.5668, and the masked outer region had arefractive index of 1.5550 (difference in refractive index between themasked and unmasked regions of 0.0118). The difference between theunmasked region and the mixture made of formulation described in Example8 was 0.0352.

Example 11

A kit having Parts I and II was made as follows:

Part 1: In a labeled 100 mL bottle, 6.000 g of pentaerythritol triallylether (70% triallyl), 13.000 g of trimethylolpropanetris(3-mercaptopropionate), 13.000 g of ATLAC (previously dissolved inacetone, filtered through a 2.5μ filter, and dried), and 0.044 g ofIrgacure™ 184 were weighed. Using a stirrer bar and a magnetic stirrer,the ingredients was stirred for about 10 minutes to give a homogenousmixture. The mixture was rotary evaporated at 50° C. for 1-2 hours toevaporate all acetone.

Part II: In another labeled 30 mL amber vial, 4.000 g of pentaerythritoltriallyl ether (70% triallyl), 8.000 g of trimethylolpropanetris(3-mercaptopropionate), and 0.660 g of amine (1838-L 3M Scotch Weld(Part A)) were weighed. Using a stirrer bar and a magnetic stirrer, theformulation was stirred for about 10 minutes to give a homogenousmixture.

Example 12

A portion of Parts I and II (from the kit of Example 11) were mixed in aratio of 2.53:1, respectively. The Part I composition was weighedcarefully in a 100 mL beaker. Based on the amount of Part I formulation,the calculated amount of Part II was added into the same beaker. The twocompositions were first mixed thoroughly by hand using a glass stirrer(glass was found to work better than metal), followed by mixing using amagnetic stirrer to form a mixture, then used immediately as describedin Example 13.

Example 13

The mixture of Example 12 was transferred to a glass plate equipped witha wire spacer. The mixture on the plate was degassed to remove trappedair. A thin quartz plate was carefully placed over the glass plate andthe plates were pressed firmly together, with the degassed mixturesandwiched between. The sandwiched mixture was cured by exposing it toultraviolet light using a UV lamp (EXFO intensity=1.5-2.0 mW/cm²) for 30minutes. The difference in the refractive index between the fully curedand the sandwiched mixture was measured to be 0.025.

Example 14

The mixture of Example 12 was transferred to a glass plate equipped witha wire spacer. The mixture on the plate was degassed to remove trappedair. A thin quartz plate was carefully placed over the glass plate andthe plates were pressed firmly together, with the degassed mixturesandwiched between. The sandwiched mixture was maintained at about 60°C. for about 40 minutes to form a sandwiched gel. The gel comprised acrosslinked polyester polymer having pentaerythritol triallyl ether (70%triallyl) and trimethylolpropane tris(3-mercaptopropionate) dispersedtherein. The sandwiched gel was masked and the central portion of thegel was exposed to ultraviolet radiation (EXFO intensity=8-10 mW/cm²)for about 5 minutes to polymerize the ene and thiol monomers, therebyforming a mixture of a thiol-ene polymer and a crosslinked polyester inthe exposed region. The difference in the refractive index between themasked and unmasked regions was measured to be 0.020.

Example 15

The mask was removed from the sandwiched gel of Example 14 and theentire sandwiched gel between the two plates was exposed to ultravioletradiation (EXFO intensity=8-10 mW/cm²) for about 2-5 minutes, therebypartially polymerizing the thiol and ene monomers in the area previouslyunder the mask. The refractive index difference between the previouslymasked region and the unmasked region was 0.007. This period of exposurewas found to provide increased stability of the refractive indexdifference between the masked and unmasked regions.

Example 16

The process described in Examples 12, 14 and 15 is repeated, except thatadditional amounts of pentaerythritol triallyl ether (70% triallyl) andtrimethylolpropane tris(3-mercaptopropionate) are added to the unexposedregion of a sandwiched gel prepared as described in Example 14. Theresulting sandwiched gel, containing the additional monomers, is thenexposed to ultraviolet radiation in the manner described in Example 15,thereby partially polymerizing the thiol and ene monomers in theunmasked area. The refractive index difference between the previouslymasked region and the unmasked region is greater than 0.007 because ofthe presence of the additional monomers.

Example 17

A kit having Parts I and II was made as follows:

Part I: In a 500 mL flask, 100 g of poly[(phenylglycidylether)-co-formaldehyde], 49.42 g of diallylether Bisphenol A, 0.2761 gof Irgacure™ 184, and 0.0552 g of N-PAL were dissolved in acetone. Themixture was then filtered through a 0.2 μm syringe filter into anotherclean 500 mL flask. The filtrate was rotary evaporated at 60° C. for 2hours to evaporate all acetone.

Part II: In another 500 mL flask, 3.27 g of tetrabutyl ammonium bromide,and 150 g of trimethylolpropane tris(3-mercaptopropionate) weredissolved in acetone. The mixture was then filtered through a 0.2 μmsyringe filter into another clean 500 mL flask. The filtrate was rotaryevaporated at 50° C. for 2 hours to evaporate all acetone.

Example 18

A portion of Parts I and 1: (from the kit of Example 17) were mixed in aratio of 1.157:1, respectively. The Part I composition was weighedcarefully in a 20 mL scintillation vial. Based on the amount of Part Iformulation, the calculated amount of Part II was added to the samevial. The two compositions were mixed thoroughly by hand using a glassstirring rod.

Example 19

Approximately 2.6 grams of the mixture of Example 18 was transferred tothe concave surface of a Samsung EyeTech UV-Clear 1.6 cover 210(schematically illustrated in FIG. 2) equipped with spacers 220 (piecesof adhesive tape with 20 mil thickness placed around the edges on theconcave side of the cover lens). The mixture 230 on the cover 210 wasdegassed to remove trapped air. A Samsung UV-Clear 1.6 base lens 240with a 5.0 base curve was carefully placed over the cover lens and thelenses were pressed firmly together, with the degassed mixture 230sandwiched between to make a lens assembly 250 (schematicallyillustrated in FIG. 3). The lens assembly 250 was maintained at 75° C.for 5½ hours to cure the sandwiched mixture 230 to a gel. The gel 230comprised a thiol-cured epoxy having diallylether Bisphenol A andtrimethylolpropane tris(3-mercaptopropionate) dispersed therein. Afterthe lens assembly 250 was cooled to room temperature, the base lens 240was then ground to plano to form an optical element.

Example 20

The lens assembly 250 of Example 19 was placed inside a hot box with alens holder in order to heat the lens assembly to a temperature of 85°C. A ZYGO interferometer was used to measure the optical path difference(OPD) pattern of the lens assembly prior to UV exposure. This OPDpattern was designated as the reference OPD pattern. A Dymax UV lampwith an integrating rod was used to produce a uniform beam ofultraviolet radiation (Intensity=53 mW/cm²). The central region of thesandwiched gel 230 in the lens assembly 250 was exposed to ultravioletradiation through a photomask with a trefoil pattern (FIG. 4) for 22minutes. A ZYGO interferometer was used to measure the OPD patterncreated in the sandwiched gel 230 as a result of the ultravioletexposure through the trefoil photomask. The reference OPD pattern wassubtracted from the new OPD pattern, and Intelliwave software was usedto create an OPD map (FIG. 5). A peak-to-valley range of 3.27 microns(corresponding to a refractive index difference of 0.01 between theirradiated and masked regions, sufficient to correct higher orderaberrations of a large percentage of the population) was obtained over a6 mm diameter in the central region of the lens.

Example 21

A kit having Parts I and II was made as follows:

Part I: In a 500 mL flask, 100 g of poly[(phenylglycidylether)-co-formaldehyde], 33.61 g of diallylether Bisphenol A, 0.2466 gof Irgacure™ 184, and 0.0740 g of N-PAL were dissolved in acetone. Themixture was then filtered through a 0.2 μm syringe filter into anotherclean 500 mL flask. The filtrate was rotary evaporated at 60° C. for 2hours to evaporate all acetone.

Part II: In another 500 mL flask, 3.27 g of tetrabutyl ammonium bromide,and 150 g of trimethylolpropane tris(3-mercaptopropionate) weredissolved in acetone. The mixture was then filtered through a 0.2 μmsyringe filter into another clean 500 mL flask. The filtrate was rotaryevaporated at 50° C. for 2 hours to evaporate all acetone.

Example 22

Portions of parts I and II (from the kit of Example 21) were mixed in aratio of 1.16:1, respectively. The Part I composition was weighedcarefully in a 20 mL scintillation vial. Based on the amount of Part Iformulation, the calculated amount of Part II was added to the samevial. The two compositions were mixed thoroughly by hand using a glassstirring rod. The mixture was degassed to remove trapped air.

Example 23

Approximately 0.3 grams of the mixture of Example 22 was transferred toa 1-inch×1-inch square glass plate equipped with spacers (pieces ofadhesive tape with 20 mil thickness placed at the corners of thesquare). Another 1-inch×1-inch square quartz plate was carefully placedover the first glass plate and the two plates were pressed firmlytogether, with the degassed mixture sandwiched between to make a testcell. The cell was maintained at 75° C. for 5½ hours to cure thesandwiched mixture to a gel. The gel comprised a thiol-cured epoxyhaving diallylether Bisphenol A and trimethylolpropanetris(3-mercaptopropionate) dispersed therein.

Example 24

The test cell from Example 23 was placed inside of a hot box with a cellholder in order to heat the cell to a temperature of 85° C. A ZYGOinterferometer was used to measure the optical path difference (OPD)pattern of the lens assembly prior to UV exposure. This OPD pattern wasdesignated as the reference OPD pattern. A Dymax UV lamp with anintegrating rod was used to produce a uniform beam of ultravioletradiation (Intensity=53 mW/cm²). The central region of the sandwichedgel in the lens assembly was exposed to ultraviolet radiation through aphotomask with a trefoil pattern (FIG. 4) for 3½ minutes. After theirradiation, the test cell was cooled to room temperature. A ZYGOinterferometer was used to measure the OPD pattern created in thesandwiched gel as a result of the ultraviolet exposure through thetrefoil photomask. The reference OPD pattern was subtracted from the newOPD pattern, and Intelliwave software was used to create an OPD map. Apeak-to-valley range of 1.6 microns was obtained over a 6 mm diameter inthe central region of the test cell. This was approximately half of themaximum potential peak-to-valley range (2.96 microns as obtained inanother test cell) for the test cell.

Example 25

Accelerated thermal aging tests were performed on the test cellirradiated as described in Example 24 in order to evaluate the stabilityof the trefoil pattern that was written in the sandwiched gel material.An assumption was made that there would be a doubling in degradationrate for every 10° C. increase in temperature (typical assumption foraccelerated aging study). Room temperature in the laboratory wasmeasured to be 23° C., and the test cell from Example 24 was kept in anoven at 83° C. (a difference of 60° C.). According to the assumption,degradation would occur 64 (or 26) times faster at 83° C. than at 23° C.(room temperature). Thus, it was calculated that aging the test cell inthe oven at 83° C. for 2 hours and 38 minutes would simulate aging it atroom temperature for one week (168 hours). The test cell was kept in theoven at 83° C., and pulled out of the oven for brief periods at varioustimes to measure the OPD pattern using the ZYGO interferometer. The testcell was cooled to room temperature prior to every measurement. Aftereach measurement, the new OPD pattern was compared to the original OPDpattern obtained in Example 24 in order to quantify the change of theOPD pattern due to accelerated thermal exposure. FIG. 6 shows a plot ofthe percent change in peak-to-valley for the trefoil pattern versussimulated time (2 hrs. 38 min. at 83° C.=1 simulated week at 23° C.).The plot shows that the peak-to-valley increased slightly above theoriginal value at first, and then decreased to about 81% of the originalvalue (degradation of only 19%) over a 2-year simulation.

Example 26

Accelerated thermal aging tests were performed on the Part I formulationof the kit of Example 21 in order to evaluate its stability. It wasassumed that there would be a doubling in aging rate for every 10° C.increase in temperature (typical assumption for accelerated agingstudy). The original refractive index of the Part I formulation measuredat room temperature was 1.5891. The Part I formulation was kept in anoven at 83° C. for 274 hours to simulate 2 years of aging at roomtemperature according to the assumption. After two years of simulatedaging, the Part I formulation was removed from the oven, and cooled toroom temperature. Its refractive index was measured to be 1.5891 (achange of 0% from the original value).

Example 27

The accelerated thermal aging test of Example 26 was performed on thePart II formulation of the kit of Example 21 in order to evaluate itsstability. The original refractive index of the Part II formulation was1.5167. After a 2-year simulation, the refractive index of the Part IIformulation had increased to 1.5188 (a change of only 0.14% from theoriginal value).

Example 28

The accelerated thermal aging test of Example 26 was performed on thesandwiched gel of Example 23 to evaluate its stability. The originalrefractive index of the sandwiched gel was 1.5758. After a 2-yearsimulation, the refractive index of the sandwiched gel was still 1.5758(a change of 0% from the original value).

Example 29

The mixture of Example 8 was used to make two lens assemblies preparedas described in Example 19 (except UV-Clear CR-39 was used in place ofSamsung EyeTech UV-Clear 1.6 for the cover and base lenses). The twolens assemblies were used in an experiment to evaluate the shelf-life ofthe sandwiched gel. One lens assembly was stored at room temperature for2 months and then irradiated using the setup described in Example 20. Apeak-to-valley range (or dynamic range) of 4.11 microns was obtained forthe trefoil pattern after about 20 minutes of irradiation. The secondlens assembly was stored at room temperature for 6 months and thenirradiated using the setup described in Example 20. A peak-to-valleyrange (or dynamic range) of 4.57 microns was obtained for the trefoilpattern after about 18 minutes of irradiation. The curing curves(peak-to-valley vs. time) for the two lenses of this example are shownin FIG. 7. The achievement of approximately similar peak-to-valley range(or dynamic range) and curing curves for each lens demonstrated that thesandwiched gel of this example has a shelf-life of at least 6 months.This has important practical implications as it means that lensassemblies with this sandwiched gel can be manufactured, stored and/ordistributed, and then custom-irradiated (with a pattern that correspondsto a patient's unique high order aberration) at a later time withoutsacrificing the magnitude (peak-to-valley range) of the correction thatcan be written.

Example 30

A kit having Parts I and II was made by intermixing the followingingredients:

Part I: 23.0 g of reactive Bisphenol A glycerolate (1glycerol/phenol)diacrylate (BPGDA, n_(D)=1.557) (Aldrich), 46.0 g ofethanol (Aldrich), 0.23 g of photoinitiator (Irgacure™ 184).

Part II: 25.0 g of reactive 2-hydroxy ethyl methacrylate (HEMA,n_(D)=1.453) (Aldrich), 25.0 g of ethanol, 0.25 g of photoinitiator(Irgacure™ 184).

Example 31-36

A series of polymerizable compositions were prepared by intermixing therelative amounts (weight basis) of Parts I and II of the kit of Example30 as shown in Table 3. Table 3 also shows the refractive indices(n_(D)) of each polymerizable composition and the correspondingrefractive indices of the polymers obtained by UV-curing each of thepolymerizable compositions.

TABLE 3 Composition No. Part II (%) Part I (%) n_(D) (uncured) n_(D)(cured) 31 0 100 1.417 1.558 32 20 80 1.413 1.535 33 40 60 1.411 1.51634 60 40 1.407 1.504 35 80 20 1.405 1.483 36 100 0 1.404 1.474

Example 37

A kit having Parts I and II was made by intermixing the followingingredients:

Part I: 50.0 g of reactive tri(propylene glycol)diacrylate (TPGDA,n_(D)=1.450) (Aldrich), 50 g of ethanol, 0.51 g of photoinitiator,Irgacure™ 184, and 0.52 g of thermal initiator, butyronitrile (AIBN)(Aldrich).

Part II: 162.8 g of reactive Bisphenol A glycerolate (1glycerol/phenol)diacrylate (BPGDA, n_(D)=1.557), 162.8 g of ethanol,1.63 g of photoinitiator, Irgacure™ 184, and 1.63 g of thermalinitiator, azoisobutyronitrile (AIBN).

Example 38-43

A series of polymerizable compositions were prepared by intermixing therelative amounts (weight basis) of Parts I and II of the kit of Example37 as shown in Table 4. Table 4 also shows the refractive indices(n_(D)) of each polymerizable composition and the correspondingrefractive indices of the polymers obtained by thermal/UV curing each ofthe polymerizable compositions.

TABLE 4 Composition No. Part II (%) Part I (%) n_(D) (uncured) n_(D)(cured) 38 0 100 1.4497 1.5595 39 20 80 1.4365 1.5431 40 40 60 1.42861.5302 41 60 40 1.4214 1.5203 42 80 20 1.4120 1.4725 43 100 0 1.40451.4560

Example 44

A kit having Parts I and II was made by intermixing the followingingredients:

Part I: An ene and a thiol of the following structures, 1% Irgacure™ 184and 1% Irgacure™ 919:

Part II: An ene and a thiol of the following structures, 1% Irgacure™184 and 1% Irgacure™ 819:

Examples 45-50

A series of polymerizable compositions were prepared by intermixing therelative amounts (weight basis) of Parts I and II of the kit of Example44 as shown in Table 5. Table 5 also shows the refractive indices(n_(D)) of each polymerizable composition and the correspondingrefractive indices of the polymers obtained by UV-curing each of thepolymerizable compositions.

TABLE 5 Composition No. Part II (%) Part I (%) n_(D) (uncured) n_(D)(cured) 45 100 0 1.6150 1.6405 46 80 20 1.5882 1.6152 47 60 40 1.56181.5889 48 40 60 1.5370 1.5652 49 20 90 1.5105 1.5403 50 0 100 1.48951.5205

Example 51

A kit having Parts I and II was made by intermixing the followingingredients:

Part I: Styrene, divinylbenzene, thiobisbenezenethiol, 1% Irgacure™ 184and 1% Irgacure™ 819.

Part II: An ene and a thiol of the following structures, 1% Irgacure™184 and 1% Irgacure™ 819:

Examples 52-57

A series of polymerizable compositions were prepared by intermixing therelative amounts (weight basis) of Parts I and II of the kit of Example51 as shown in Table 6. Table 6 refractive indices (n_(D)) of eachpolymerizable composition and the refractive of the polymers obtained byUV-curing a polymerizable composition.

TABLE 6 Composition No. Part II (%) Part I (%) n_(D) (uncured) n_(D)(cured) 52 100 0 1.6733 HAZY 53 80 20 1.6396 HAZY 54 60 40 1.6030 HAZY55 40 60 1.5692 HAZY 56 20 90 1.5332 HAZY 57 0 100 1.4850 1.5125

Example 58

A kit having Parts I and II was made by intermixing the followingingredients:

Part I: An ene prepared as in Example 6, a thiol of the followingstructure, 1% Irgacure™ 184 and 1% Irgacure™ 819:

Part II: An ene and a thiol of the following structures, 1% Irgacure™184 and 1% Irgacure™ 819:

Examples 59-64

A series of polymerizable compositions were prepared by intermixing therelative amounts (weight basis) of Parts I and II of the kit of Example58 as shown in Table 7. Table 7 refractive indices (n_(D)) of eachpolymerizable composition and the corresponding refractive indices ofthe polymers obtained by UV-curing each of the polymerizablecompositions.

TABLE 7 Composition No. Part II (%) Part I (%) n_(D) (uncured) n_(D)(cured) 59 100 0 1.5608 1.5927 60 80 20 1.5421 1.5772 61 60 40 1.52911.5637 62 40 60 1.5123 1.5474 63 20 90 1.4980 1.5319 64 0 100 1.48521.5170

Example 65

A kit having Parts I and II was made by intermixing the followingingredients:

Part I: An ene and a thiol of the following structures, 1% Irgacure™ 184and 1% Irgacure™ 819:

Part II: An ene and a thiol of the following structures, 1% Irgacure™184 and 1% Irgacure™ 819:

Examples 66-71

A series of polymerizable compositions were prepared by intermixing therelative amounts (weight basis) of Parts I and II of the kit of Example65 as shown in Table 8. Table 8 also shows the refractive indices(n_(D)) of each polymerizable composition and the correspondingrefractive indices of the polymers obtained by UV-curing each of thepolymerizable compositions.

TABLE 8 Composition No. Part II (%) Part I (%) n_(D) (uncured) n_(D)(cured) 66 100 0 1.5742 1.6124 67 80 20 1.5542 1.5962 68 60 40 1.53711.5763 69 40 60 1.5182 1.5547 70 20 90 1.5009 1.5341 71 0 100 1.48521.5170

Example 72

A kit having Parts I and II was made by intermixing the followingingredients:

Part I: An ene as prepared in Example 6, an ene and a thiol of thefollowing structures, and 1% Irgacure™ 184:

Part II: An ene and a thiol of the following structures, 1% Irgacure™184 and 1% Irgacure™ 819:

Example 73-78

A series of polymerizable compositions were prepared by intermixing therelative amounts (weight basis) of Parts I and II of the kit of Example72 as shown in Table 9. Table 9 also shows the refractive indices(n_(D)) of each polymerizable composition and the correspondingrefractive indices of the polymers obtained by UV-curing each of thepolymerizable compositions.

TABLE 9 Composition No. Part II (%) Part I (%) n_(D) (uncured) n_(D)(cured) 73 100 0 1.4802 1.5121 74 80 20 1.4990 1.5300 75 60 40 1.51201.5423 76 40 60 1.5306 1.5654 77 20 90 1.5502 1.5847 78 0 100 1.56741.5905

Example 79

A kit having Parts I and II was made by intermixing the followingingredients:

Part I: An ene as prepared in Example 6 (18 g), a thiol of the followingstructure (10.98 g), Brij 52 (Aldrich) (surfactant, 0.02 g), Brij 58(Aldrich) (surfactant, 0.02 g), Irgacure™184 (0.161 g) and Irgacure™ 819(0.119 g):

Part II: An ene (50 g) and a thiol (32.66 g) of the followingstructures, Irgacure™ 184 (0.27 g):

Examples 80-85

A series of polymerizable compositions were prepared by intermixing therelative amounts (weight basis) of Parts I and II of the kit of Example79 as shown in Table 10. Table 10 shows the refractive indices (n_(D))of each polymerizable composition and the corresponding refractiveindices of the polymers obtained by UV-curing each of the polymerizablecompositions.

TABLE 10 Composition No. Part II (%) Part I (%) n_(D) (uncured) n_(D)(cured) 80 100 0 1.4820 1.5104 81 80 20 1.5094 1.5380 82 60 40 1.53271.5648 83 40 60 1.5571 1.5906 84 20 90 1.5786 1.6150 85 0 100 1.60041.6405

It will be appreciated by those skilled in the art that variousomissions, additions and modifications may be made to the processesdescribed above without departing from the scope of the invention, andall such modifications and changes are intended to fall within the scopeof the invention, as defined by the appended claims.

1. An optical element comprising: a first transparent layer and a secondtransparent layer; and a cured polymer layer sandwiched between thefirst and second transparent layers, wherein, prior to curing, thepolymer layer comprises a matrix polymer having a monomer mixturedispersed therein, wherein the matrix polymer is the product of achemical reaction between at least a thiol monomer, a crosslinkingagent, and a polymer, wherein the crosslinking agent is selected fromthe group consisting of polyethyleneimine and tetraalkyl ammoniumhalide, wherein the polymer is selected from the group consisting ofunsaturated polyester, unsaturated polystyrene, unsaturatedpolyacrylate, epoxy polymer, isocyanate polymer, and mixtures thereof,and wherein the monomer mixture comprises a thiol monomer and at leastone second monomer selected from the group consisting of ene monomer andyne monomer.
 2. The optical element of claim 1 in which the thiolmonomer is multifunctional.
 3. The optical element of claim 1 in whichthe second monomer is multifunctional.
 4. The optical element of claim 1wherein the matrix polymer further comprises one or more additivesselected from the group consisting of photoinitiator, polymerizationinhibitor, antioxidant, photochromic dye, and UV-absorber.
 5. Theoptical element of claim 1 wherein the matrix polymer is provided in theform of a film.
 6. The optical element of claim 5 in which the film isprotected by a coating.
 7. An optical element, comprising: a first lens;a cover; and a cured matrix polymer sandwiched between the first lensand the cover, the matrix polymer, prior to curing, having a polymer, acrosslinking agent, and a monomer mixture dispersed therein, wherein thepolymer is selected from the group consisting of unsaturated polyester,unsaturated polystyrene, unsaturated polyacrylate, epoxy polymer,isocyanate polymer, and mixtures thereof, wherein the monomer mixturecomprises a thiol monomer and at least one second monomer selected fromthe group consisting of ene monomer and yne monomer, and wherein thecrosslinking agent is selected from the group consisting ofpolyethyleneimine and tetraalkyl ammonium halide.
 8. The optical elementof claim 7 in which the cover is a second lens.
 9. The optical elementof claim 7 in which the first lens is a lens blank.
 10. The opticalelement of claim 7 in which the matrix polymer comprises an amount of apolymerization inhibitor that is effective to at least partially inhibitpolymerization of the monomer mixture.
 11. An optical element,comprising: a first lens; a cover; and a cured polymer mixturesandwiched between the first lens and the cover, the polymer mixturecomprising a first polymer, a crosslinking agent, and a second polymer,wherein the first polymer is selected from the group consisting ofpolyester, polystyrene, polyacrylate, thiol cured epoxy polymer, thiolcured-isocyanate polymer, and mixtures thereof, wherein the secondpolymer is selected from the group consisting of thiol-ene polymer andthiol-yne polymer, and wherein the crosslinking agent is selected fromthe group consisting of polyethyleneimine and tetraalkyl ammoniumhalide.
 12. The optical element of claim 11 in which the cover is asecond lens.
 13. The optical element of claim 11 in which the cover is acoating.
 14. The optical element of claim 11 in which the first lens isa lens blank.
 15. The optical element of claim 1 in which the polymermixture comprises at least one region in which the first polymer has afirst refractive index and the second polymer has a second refractiveindex that is different from the first refractive index.
 16. The opticalelement of claim 15 in which the polymer mixture comprises at least oneadditional region in which the second polymer has a refractive indexthat is different from the second refractive index.